[fullerton]

Originally Posted by T3h_Clap

or look at my journal, or shoot me a PM.



<-- has to make changes after his install this weekend too!

good thing alignments only cost me dinner

good thing i have lifetime alignments.

[T3h_Clap]

Originally Posted by fullerton

what caster do i want to shoot for?

personally

camber > caster

at least for autox.

this gets confusing but follow along

you don't get enough camber from each degree of caster that you lose in static camber b/c you set them up for caster.

did that make sense?

setup for caster you get less static camber, but the gained camber from the new caster is less then what you would've gained if you just maxed the static camber with no caster change.

ok that made more sense.

but really it's up to you.

i'm not sure what adding caster does (with the top hat) to your alignment #s (besides changing caster....).

with more negative camber you get more toe out, which is good for autox, but i'm not 100% what adding more positive caster will do to your toe.

i'm making less sense as i go arn't i?

[KarlSTI]

Looking good. I tried to order the PDE Camber Plates today from PDE and they were out of stock....

[fullerton]

make the order. they'll get them to you in a few weeks.

[KarlSTI]

Originally Posted by fullerton

make the order. they'll get them to you in a few weeks.

OK, I guess I'll call them since I couldn't order on line with an empty shopping basket.... Hmmm, can't find a phone number for them....

[fullerton]

ok, after a bit of searching, looks like the extra positive camber of having them installed correctly would slow turn-in.

any thoughts? from what i have read, adding positive camber (moving the top of the strut towards the driver) is not a good thing.

I would think you want 0 caster...

Thoughts?

[fullerton]

Originally Posted by Effects of Positive Caster

...a vehicle with positive caster (point of load ahead of the point of contact) to be harder to steer away from the straight ahead position. ...

Vehicles usually have some positive caster specified since this promotes directional stability, however, excessive positive caster can cause two problems. The first is that excessive caster will cause a high level of road shock to be transmitted to the driver when the vehicle hits a bump, etc. The second problem is that a tire/wheel assembly with positive caster has a tendency to toe inward when the vehicle is being driven. If one side has more positive caster than the other, this causes it to toe inward with more force than the other side. This will cause a lead or pull to the side with least amount of positive caster.

Positive=bad?

When a tire has a Negative caster condition, where the projected steering axis point of load is behind the tire point of contact, a vehicle will have a tendency to be easier to steer but will lack directional stability. A vehicle with negative caster is affected by any road surface variation such as small road irregularities or bumps. With the point of load pushing the tire along (negative caster), any bumps or road irregularities which are encountered have a tendency to immediately affect directional stability and vehicle handling.

I'll take some tramlining for quicker turn-in.

[fullerton]

info from here:
http://www.ingallseng.com/terms.htm#FrontCaster

and a nice diagram:

[fullerton]

....as i talk to myself....

this thread says the more the better basically:
Caster questions

so my thoughts before are, not surprisingly, wrong.

[T3h_Clap]

you do not want ZERO caster.

caster is good, as long as you have power steering.

but if you had a choice between stock caster and lots of negative camber vs. more caster and less then lots of negative camber. i'd do option 1

and most places when they talk about negatives of postive caster they usually talk about 10 degrees not 5.

[fullerton]

I was able to easily rotate the top hats without undoing more than the three bolts on the plates.

Just got back from the new alignment. I wanted to see what these plates would max out at, and here you go. Too much camber IMHO, but they fixed the toe out back this time. I'll drive like this until I install the Whiteline RCA's.

Here are my specs, before rotation of tops and then after :

Left Front:
Camber: -2.6 : -3.6
Caster: 4.1 : 5.7
Toe: .02 : .02
SAI: 15.3 : 12.7

Right Front:
Camber: -2.6 : -3.5
Caster: 4.0 : 5.7
Toe: -.03 : -.03
SAI: 16 : 13

Total Front:
Cross Camber: 0 : -.1
Cross Caster: .01 : 0
Total Toe: -.01 : -.01

Left Rear:
Camber: -1.3 : -1.6
Toe: -.07 : .03

Right Rear:
Camber: -1.4 : -1.8
Toe: .1 : .01

Total Rear:
Total Toe: .17 : .03
Thrust Angle: -.01 : .01




Overall it is an improvement over last week's alignment, but I don't think -3.6° of camber is necessary. I think I'll move in the plates a bit and shoot for -1.75° for the street, have them zero the toe again and then just drop it a few spots for the track.

Anyone know what each hole means for toe and camber?

[fullerton]

Oh- 3.6° looks ridiculous on the car. It looks like there is something wrong, especially if you don't know what camber is about.

[fullerton]

And I'm looking through this month's Car & Driver where they rate the Audi R8, Porsche 911 and Aston Martin V-8 Vantage.

I decided to compare my roughly $40,000 (with mods) Subaru with the Audi. Both are AWD 6-speed cars that I love. I'll use my 100 octant tune because with the price difference savings I could afford 100 all the time. Let me know if you can find any other comparison numbers.

Price:
Audi: $120,970
STi: $40,000 (High Est.)

STi wins


Crank HP:
Audi: 420 @ 7800
STi: 388 @ 5000

Audi wins


Crank Torque:
Audi: 317 @ 4500
STi: 491 @ 3300

STi wins


Redline:
Audi: 8000
STi: 7000

Audi wins


Curb Weight:
Audi: 3540
STi: 3263 (though probably less, as I have reduced some weight)

STi wins


LB per HP:
Audi: 8.428
STi: 8.409

STi wins


Top Speed:
Audi: 187 (Drag Limited
STi: 173 (Redline Limited)

Audi wins


Fuel Economy:
Audi: 13/19
STi: 18/24

STi wins


Brakes:
Audi: 15f/14r
STi: 12/7f/12.3r

Audi wins


Audi: 4 wins
STi: 5 wins



Not bad for a car 1/3th the price!

[nandanrp]

Braking distance is more important than the size of the rotors... and weight/tire selection play roles in how good the braking is, too.

[fullerton]

I'll see if I can find the distance for the R8, but I would assume that similarly weighted cars will slow at the same rate on the same rotors. Bigger rotors would most likely increase braking power.